Résumé
The development of an efficient transfection system in livestock cells is an important step towards investigating gene transfer and the functioning and production of transgenic animals. Important factors involved in cationic liposome mediated gene transfer were evaluated through in vitro transfection of bovine, caprine and ovine fibroblast cells. Transfection of plasmid DNA complexes of different commercially available liposomes (Lipofectamine, Lipofectin, Cellfectin and DMRIE-C; Gibco-BRL, USA) was evaluated utilizing the following parameters: DNA/liposome ratio, cell density, DNA conformation, and the effect of transfection time on the efficiency of bovine fibroblasts to express a reporter gene. The effects and concentrations of liposomes were also evaluated in caprine and ovine fibroblasts. Lipofectamine alone and Lipofectamine with Plus reagent induced high-frequency expression of beta-galactosidase and neo genes in all cells evaluated (47 and 88.3%, respectively). Regarding phenotype, chromosomal stability was similar in transfected and non-transfected cells. The parameters set in this study will establish a foundation for utilizing transfected fibroblast cells to generate transgenic animals through nuclear transfer technology and gene function studies.
Sujets)
Animaux , Animal génétiquement modifié , Bovins/génétique , Fibroblastes/transplantation , Liposomes , Transfection/méthodes , ADN , Cytomegalovirus , Numération cellulaire , Cellules cultivées , Expression des gènes , Ovis/génétique , Plasmides/génétique , Reproductibilité des résultats , Suidae/génétique , Vecteurs génétiques , beta-Galactosidase/génétiqueRésumé
An association of two techniques, nuclear transfer (NT), and transfection of somatic animal cells, has numerous potential applications and considerable impact, mainly in agriculture, medicine, pharmacy, and fundamental biology. In addition, somatic cell nuclear transfer is the most efficient alternative to produce large transgenic animals. We compared in vitro and in vivo developmental capacities of NT using fibroblast cells isolated from a 14-month-old cloned Simmental heifer (FCE) vs the same line transfected with a plasmid containing neomycin-resistant genes (TFCE). There were no significant differences (P > 0.5) in either fusion (116/149 = 78% vs 216/301 = 72%), cleavage (78/116 = 67% vs 141/216 = 65%) and blastocyst (35/116 = 30% vs 52/216 = 24%) rates or in pregnancy rate at 30 to 35 days after embryo transfer (2/17 vs 3/17) between NT using FCE and TFCE, respectively. Transfection and long-term in vitro culture of transfected cells did not affect developmental capacity of NT embryos up to 40 days of gestation
Sujets)
Animaux , Femelle , Grossesse , Animal génétiquement modifié , Bovins/génétique , Transfert d'embryon , Fibroblastes/transplantation , Noyau de la cellule/transplantation , Blastocyste/physiologie , Clonage d'organisme , Clones cellulaires/physiologie , Réaction de polymérisation en chaîne , Transfection/méthodesRésumé
cDNAs dos genes bone morphogenetic protein-2 (BMP-2) e bone morphogenetic protein-4 (BMP-4) foram sintetizados a partir de RNA total extraído de tecidos ósseos de pacientes que apresentavam trauma facial (fraturas do maxilar entre o 7º e o 10º dia pós-trauma) e clonados num vetor para expressão em células mamíferas, sob controle do promotor de citomegalovírus (CMV). Os vetores contendo os genes BMP-2 e o BMP-4 foram utilizados para a transfecção de fibroblastos bovinos. mRNAs foram indiretamente detectados por RT-PCR nas células transfectadas. As proteínas BMP-2 e BMP-4 foram detectadas mediante análises de Western blot. Os resultados demonstram a possibilidade de produção desses fatores de crescimento celular em fibroblastos bovinos. Essas células poderão ser utilizadas como fontes doadoras de material genético para a técnica de transferência nuclear na geração de animais transgênicos.